A guy might lift every day, he might get massive, he might even start to intimidate other people a little (hopefully with his size and not his personality!), but there's still one thing in that gym that chills him to the bone. There's chance our guy does so little of it that he'd have trouble running round the block...
Cardio can be boring, but it is important for anyone who values fitness as well as aesthetics. People looking to get big have traditionally avoided aerobic exercise because of the potential for muscle loss, but there is a group of researchers out there that might have thrown that idea on its head.
Scientists in the US have been looking at what happens in muscle tissue after aerobic exercise. A group of eight active men were asked to cycle for one hour, after which they received either a macronutrient-balanced formula made up of carbs, protein, and fat, containing about the same amount of energy in a small meal, or a noncaloric placebo.
Muscle biopsies were taken from each participant both at rest, and after each treatment. The scientists looked at the levels of various gene products involved in muscle synthesis and muscle breakdown.
The investigators were very surprised to find that aerobic exercise appeared to stimulate the body to synthesise muscle, not only when subjects were fed after exercise, but also when they received the placebo treatment that did not deliver any nutrition or energy.
They also discovered that muscle breakdown pathways were concurrently activated in those subjects who had the placebo, whereas they were not activated in those athletes who received post-workout nutrition.
The scientists identified a specific gene product that was made after aerobic activity. It is thought to create an anabolic environment where extra muscle mass is laid down to prepare the body for future exercise. These findings go against the dogma that aerobic exercise causes muscle breakdown.
Cardio can be an energy intensive form of exercise, and this is so important to take into account if you are trying to combine fitness with muscle gains - without a sufficient intake of protein and energy, muscle mass will still be lost, so eat up.
These findings should give people the confidence to add cardio, alongside carefully planned and timed nutrition, into their regime without fear of losing muscle mass.
Reidy PT, Konopka AR, Hinkley JM, Suer MK, Harber MP. The effect of feeding during recovery from aerobic exercise on skeletal muscleintracellular signaling. Int J Sport Nutr Exerc Metab. 2014 Feb;24(1):70-8.